Removal of pesticide residues from fresh produce is important to reduce pesticide exposure to humans. A new study, published in the Journal of Agricultural and Food Chemistry on Thursday, found that baking soda could remove far more pesticide from the surface of an apple than just tap water or a bleach rinse.
This study investigated the effectiveness of commercial and homemade washing agents in the removal of surface and internalized pesticide residues from apples.
Surface-enhanced Raman scattering (SERS) mapping and liquid chromatography tandem mass spectrometry (LC–MS/MS) methods were used to determine the effectiveness of different washing agents in removing pesticide residues.
Surface pesticide residues were most effectively removed by sodium bicarbonate (baking soda, NaHCO3) solution when compared to either tap water or Clorox bleach.
Using a 10 mg/mL NaHCO3 washing solution, it took 12 and 15 min to completely remove thiabendazole or phosmet surface residues, respectively.
This study gives us the information that the standard postharvest washing method using Clorox bleach solution for 2 min is not an effective means to completely remove pesticide residues on the surface of apples.
The NaHCO3 method is more effective in removing surface pesticide residues on apples.
In the presence of NaHCO3, thiabendazole and phosmet can degrade, which assists the physical removal force of washing.
However, the NaHCO3 method was not completely effective in removing residues that have penetrated into the apple peel.
The overall effectiveness of the method to remove all pesticide residues diminished as pesticides penetrated deeper into the fruit.
In practical application, washing apples with NaHCO3 solution can reduce pesticides mostly from the surface.
Peeling is more effective to remove the penetrated pesticides; however, bioactive compounds in the peels will become lost too.
Source: Journal of Agricultural and Food Chemistry, USA.